Merge pull request #4943 from pathawks/fp/fix-layout-var-overflow

Merge pull request 4943

features/layout_data.feature

@@ -35,3 +35,36 @@ Feature: Layout data
     When I run jekyll build
     Then the "_site/index.html" file should exist
     And I should see "page content\n foo: my custom data" in "_site/index.html"
+
+  Scenario: Inherit custom layout data and clear when not present
+    Given I have a _layouts directory
+    And I have a "_layouts/default.html" file with content:
+      """
+      ---
+      bar: i'm default
+      ---
+      {{ content }} foo: '{{ layout.foo }}' bar: '{{ layout.bar }}'
+      """
+    And I have a "_layouts/special.html" file with content:
+      """
+      ---
+      layout: default
+      foo: my special data
+      bar: im special
+      ---
+      {{ content }}
+      """
+    And I have a "_layouts/page.html" file with content:
+      """
+      ---
+      layout: default
+      bar: im page
+      ---
+      {{ content }}
+      """
+    And I have an "index.html" page with layout "special" that contains "page content"
+    And I have an "jekyll.html" page with layout "page" that contains "page content"
+    When I run jekyll build
+    Then the "_site/index.html" file should exist
+    And I should see "page content\n foo: 'my special data' bar: 'im special'" in "_site/index.html"
+    And I should see "page content\n foo: '' bar: 'im page'" in "_site/jekyll.html"

lib/jekyll/convertible.rb

@@ -209,10 +209,13 @@ module Jekyll
 
       used = Set.new([layout])
 
+      # Reset the payload layout data to ensure it starts fresh for each page.
+      payload["layout"] = nil
+
       while layout
         Jekyll.logger.debug "Rendering Layout:", path
         payload["content"] = output
-        payload["layout"]  = Utils.deep_merge_hashes(payload["layout"] || {}, layout.data)
+        payload["layout"]  = Utils.deep_merge_hashes(layout.data, payload["layout"] || {})
 
         self.output = render_liquid(layout.content,
                                     payload,

lib/jekyll/renderer.rb

@@ -136,10 +136,13 @@ module Jekyll
 
       used   = Set.new([layout])
 
+      # Reset the payload layout data to ensure it starts fresh for each page.
+      payload["layout"] = nil
+
       while layout
         payload['content'] = output
         payload['page']    = document.to_liquid
-        payload['layout']  = Utils.deep_merge_hashes(payload['layout'] || {}, layout.data)
+        payload['layout']  = Utils.deep_merge_hashes(layout.data, payload["layout"] || {})
 
         output = render_liquid(
           layout.content,